CVE-2022-49410: tracing: Fix potential double free in create_var_ref()

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-02-26 · updated 2026-06-17
Weakness: CWE-415

Description

In the Linux kernel, the following vulnerability has been resolved: tracing: Fix potential double free in create_var_ref() In create_var_ref(), init_var_ref() is called to initialize the fields of variable ref_field, which is allocated in the previous function call to create_hist_field(). Function init_var_ref() allocates the corresponding fields such as ref_field->system, but frees these fields when the function encounters an error. The caller later calls destroy_hist_field() to conduct error handling, which frees the fields and the variable itself. This results in double free of the fields which are already freed in the previous function. Fix this by storing NULL to the corresponding fields when they are freed in init_var_ref().

Affected products

Linux kernel: from 4.17 before 4.19.247; from 4.20 before 5.4.198; from 5.5 before 5.10.121; from 5.11 before 5.15.46; from 5.16 before 5.17.14; from 5.18 before 5.18.3 — fixed in 4.19.247, 5.10.121, 5.15.46, 5.17.14, 5.18.3, 5.4.198

How to fix

Upgrade to a fixed version: Linux kernel 4.19.247, 5.10.121, 5.15.46, 5.17.14. Check the vendor advisory for mitigations.

References

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